This revised competitive renewal will have five subprojects that deal with the various aspects of diabetes complicating pregnancy. Subproject 1 will investigate the independent effects of pregnancy and exercise training on early phase insulin release in non-diabetic women and those with prior gestational diabetes. Subproject 2 will examine the growth and development of infants born to gestational diabetics. Subproject 3 is to evaluate the impact of postnatal nutrition on growth and development of infants with fetal growth retardation. This project will evaluate the role of psychosocial intervention in improving the nutritional and developmental outcome of infants with intrauterine growth retardation. Subproject 4 will test the hypothesis that systemic hypoglycemia and hyperglycemia will result in circulatory, metabolic and blood brain barrier permeability changes, which may place the fetus and neonate at higher risk for hypoxic- ischemic injury, and/or other CNS injury. Subproject 5 will examine the cellular regulatory mechanism of fetal growth and development. The major emphasis is to examine the contribution of maternal IGF on embryonic IGF and TGF-B gene expression and fetal differentiation. This PERC consists of five projects with 18 investigators of various disciplines that will examine the various aspects of fetal growth: the role of IGF on fetal growth and differentiation, the effects of fetal growth abnormalities, i.e. macrosomic and intrauterine growth retardation, and the effects of exercise on glucose metabolism during pregnancy.